From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sujit K M Subject: Re: PREEMPT_RT (2.6.33-rt17) disabled printk-to-console after console_init Date: Thu, 20 May 2010 15:02:10 +0530 Message-ID: References: <201005201233.56877@zigzag.lvk.cs.msu.su> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: Thomas Gleixner , linux-rt-users@vger.kernel.org, linux-kernel@vger.kernel.org To: "Nikita V. Youshchenko" Return-path: Received: from mail-qy0-f171.google.com ([209.85.221.171]:34126 "EHLO mail-qy0-f171.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753943Ab0ETJcM convert rfc822-to-8bit (ORCPT ); Thu, 20 May 2010 05:32:12 -0400 In-Reply-To: Sender: linux-rt-users-owner@vger.kernel.org List-ID: Sorry does not help as it is very old and does not seem to provide information regarding Real Time Linux. But the section for setserial -g /dev/ttyS[01] and /etc/inittab modifications are pointer to the changes required for Real Timliness. The problem is that baud rate of the COM/TTY port may require some modi= fication. I Think you will need to have an Critical Section for the Driver to timeout in sync with the baud rate. Hope what I have said makes sense. On Thu, May 20, 2010 at 2:55 PM, Sujit K M wrote: > http://www.vanemery.com/Linux/Serial/serial-console.html > > Could this be of help. > > On Thu, May 20, 2010 at 2:03 PM, Nikita V. Youshchenko wrote: >>> > I could not get dmesg output to console/serial and >>> > klogd(/var/log/messages) anymore with 2.6.33-rt17 _after_ the ker= nel >>> > boot is done(on non-RT kernel it works fine). I made below change= s it >>> > starts to work again, however I'm unsure how safe the change is. >>> > Please advise. >>> >>> Well, obviously it's unsafe if you remove safety checks. And if you >>> care to look at the changelog of kernel/printk.c you'll find out wh= y. >> >> Hmm... did a quick look and could not find anything related there. >> Could you please give a pointer? >> -- >> To unsubscribe from this list: send the line "unsubscribe linux-rt-u= sers" in >> the body of a message to majordomo@vger.kernel.org >> More majordomo info at =A0http://vger.kernel.org/majordomo-info.html >> > > > > -- > -- Sujit K M > > blog(http://kmsujit.blogspot.com/) > --=20 -- Sujit K M blog(http://kmsujit.blogspot.com/) -- To unsubscribe from this list: send the line "unsubscribe linux-rt-user= s" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html